So, if I set up a back-and-forth conversation where I asked five questions and got sent five responses, would that count as one text or ten texts towards the monthly limit?

I can think of a case or two where the pricing might make sense. But if we're really being honest, I'd probably just use the service to test my assumptions and prove out the model. Then, if the numbers looked good, I'd do the Twilio integration myself to save a little money and remove the additional dependency.

This is probably exactly the wrong group of people to ask about pricing, though, because many of us know what Twilio costs and can do the integration ourselves. It's the normal business owners who'll think your product is black magic.